just wait till TPPA kicks in. It will have allow blocking of all sorts of Parallel importing if the NZ firms selling products complain. For instance Random House will be able to block books imported from Amazon, and force you to buy from local booksellers. Ditto with videos and any other product that is sold in NZ by legitimate sellers. If you try to purchase outside of NZ you are infringing the TPPA agreement and the penalties can be horrendous.
To be frank, it's not much of a point in my view. It's like ABC holdings saying that they had paid Canon $$$$ to be the authorised dealer with the exclusive rights to sell Canon cameras in NZ, and so the force of the law and muscle of Canon's legal department should be used to stop Kiwis buying the camera's for less off (say) Amazon.